Process for producing wrinkle resistant cellulosic textile materials



United States Patent Ofifice 3,072,45fi Patented Jan. 8, 1963 A nonexclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States America.

This invention relates to the treatment of cellulosic tex tiles in order to make them resistant to creasing and wrinkling.

It is well known that textiles which resist the formation of wrinkles and creases during use have long been preferred by consumers. Items, of which crease, muss, and wrinkle resistance are desirable characteristics include clothing, bed spreads, sheets, pillow cases, drapery and upholstery material, Slipcovers, and others. Of these, in clothing, which usually requires frequent ironings to maintain a smooth appearance, Wrinkle resistance is most important.

Various compounds have been applied to textiles to impart crease and wrinkle resistance, the most widely used ones being cyclic ethyleneurea-formaldehyde resins, urea-formaldehyde resins, melamine-formaldehyde resins, epoxy ethers, and formaldehyde. These compounds impart varying degrees of wrinkle resistance to the textiles, depending on the amount and type of wrinkle resistance agent used, the catalyst used, and the method of curing employed. Such textiles are usually called minimum care or wash-and-wear fabrics.

It is also important that the wrinkle resistant textiles be resistant to fiber damage and discoloration due to retention of chlorine. upon hypochlorite bleaching. Of equal importance is the durability. of wrinkle-resistance finishes to both home and the more vigorous commercial launderings. With many of the above creaseproofing agents there is a compromise between maximum creaseresistance to give a durable finish, and the susceptibility of the finish to degradation by retention of chlorine. In the case of formaldehyde, one of the greatest drawbacks is the precise control of conditions required for curing.

It is the purpose of this invention to produce a wrinkle resistance finish which will impart to textiles maximum crease resistance but negligible chlorine retention and damage due to such retention. Another object of this invention is to produce a crease resistance finish stable under acidic or alkaline conditions, durable to laundering and bisulfite or perborate bleaching. The crease resistance finish can be applied to textiles using a wide range of treating conditions. This is commercially advantageous.

The crease resistance finish which is the subject of this invention involves the reaction product of formaldehyde (including sources such as paraformaldehydes) and the ureide of mesooxalic acid (alloxan). The latter compound is represented by the formula:

The finishing agent can be prepared by reacting from 1 to- 4 or more moles of formaldehyde with one mole of the ureide under acidic conditions (pH 2-6) in sufiicient water to give a 33 /3 percent solution of the reaction product. At least two moles formaldehyde is required to prepare the dimethylol compound, however less can be used to prepare a partially methylolated compound. The solution thus prepared is diluted to the padding concentration and padded onto a cellulosic textile immediately or up to times in excess of three months.

In accordance with the invention an aqueous solution prepared as described above, and containing from 1 to 20 percent of the reaction product containing 2 or more moles of formaldehyde in combination with 1 mole of the ureide, is padded onto the cloth by passing through efficient squeeze rolls, for example, using two dips and two hips to give dry add-ons of 0.01 percent to 5 or more percent based on the weight of the dry cloth. About 0.5 percent to 3 percent by weight, of a catalyst, based on the total weight of the padding bath, is added to the padding bath to facilitate curing, and to produce a more durable finish. Catalysts which can be used to promote curing include mineral acids, various salts of strong acids, such as ammonium salts, alkanolamine salts, metallic salts of strong acids and weak bases, such as Zinc nitrate and magnesium chloride.

The curing step, the reaction of the formaldehydeureide with the textile is carried out by the usual pro cedure. The padded textile is dried at an elevated temperature, for example, 60-70 C. for 7 minutes then further heated to eiiect the curing. Improved properties are obtained at l20160 C. from 0.5 to 5 minutes. Curing temperatures above 160 C. are not generally employed, as they have a degradative efiect on the fabric. The curing time is temperature dependent, and can vary over a wide range. Thus, improved properties can be obtained at 160 C. for 30 to 60 seconds. The curing step is best followed, by an after wash with a non-ionic detergent, and 1 to 2 percent sodium perborate to remove any excess unreacted crease resistance agent and catalyst, to remove any discoloration brought on by curing, and to improve the hand of the textile.

The process to which this invention relates can be used to treat any hydrophilic fibrous cellulosic textiles such as cotton, linen, ramie, jute, regenerated cellulose, and others.

The following examples are given as illustrations and are not by any means intended to limit the scope of this invention. All percentages given in the examples are percentages by weight of the total solution. The fabrics were tested by the following methods: crease recovery angle, Monsanto method, American Society for Testing Materials (ASTM), Standards for Textile Materials D1295- 5 3T, tearing strength, Elmendorf Method ASTM designation Dl4-24-56T; damage caused by retained chlorine (scorch test), American Association of Textile Chemists and Colorists tentative test method 69-1952; wash-and wear (appearance), AATCC tentative test method 88- 1958. Two types of laundering were used to test the durability of the finish: ten home-type launderings were performed in an agitator-type home automatic washer with a household detergent, 0.02% available chlorine in hot water, and followed by drying in a tumble dryer. The other laundering procedure Was the more vigorous one described in AATCC test method 14-53. To test acid durability the samples were allowed to stand for 30 minutes at C. in a stripping solution (50 times the sample Weight) containing 5% urea and 1.5% phosphoric acid, rinsed in water, and dried in a tumble dryer.

EXAMPLE 1 A 33 /5 water solution of alloxan was prepared in the following manner: alloxan was dissolved in 2.8 times its weight in water and sufficient 36.3% formaldehyde solution was added to afford a mole ratio of formaldehyde to alloxan of 2:1. This solution, pH 3, of 33 /s% solids concentration was allowed to stand overnight at room ternperatnre. After this time the 33 /a% solution was diluted with sufiicient water to give a 7% solids concentration, and by weight of hydrated magnesium chloride (MgCl -6H O) was added as catalyst. The treating solution was padded onto a sample of 80 x 80 cotton print cloth to give a 7080% wet pickup. The wet fabric was dried at original dimensions for seven minutes at 60 C., and then cured at original dimensions for 3 minutes at 160 C. The curing step was followed by an after wash in warm water with a nonionic detergent, and 0.2% sodium perborate added, and then tumble drying. The finished fabric possessed a crease recovery angle of 275 (warp-l-fill) while an untreated, after-washed sample had a crease recovery angle of only 187 (warp-l-fill).

EXAMPLE 2 A sample treated as described in Example 1 was subjected to the urea-phosphoric acid stripping procedure. The crease recovery angle of the fabric after stripping was 133 (warp), when compared with that of the original treated fabric 139 (warp) shows that severe acidic conditions do not remove the finish from the fabric. The crease recovery angle of the untreated fabric is 95 (warp).

EXAMPLE 3 For comparison purposes the following percent solutions of alloxan -2CH O were prepared and applied to O 80 x 80 cotton print cloth with 1.5% MgCl -6H O as catalyst, and processed as described in Example 1:

A. A 33 /a% solution of the finishing agent prepared as in Example 1, was diluted with sufficient water to give a 1% solids concentration.

B. A 33%% solution of the finishing agent, prepared as described in Example 1, was diluted with sufiicient water to give a 5% solids concentration.

C. A 33 /a% solution of the finishing agent, prepared as described in Example 1, was diluted with sufiicient water to give a 7.5% solids concentration.

D. A 33 /s% solution of the finishing agent, prepared as described in Example 1, was diluted with sufiicient Water to give a 10% solids concentration.

E. A 33 /s% solution of the finishing agent, prepared as described in Example 1, was diluted with sufiicient water to give a solids concentrations.

F. A 33 /s% solution of the finishing agent, prepared as described in Example 1, was diluted with sufiicient water to give a solids concentration.

To determine the eifect of curing conditions on the physical properties of the finished fabric, a series of samples, treated with a solution containing 7% alloxan 2011 0 and 1.5 MgCl -6H O, prepared as described in Example 1, were dried for 7 minutes at 60 C., and cured as listed in Table 11. After curing the samples were given 4 an after wash and tumble-dried as described in Example 1.

Table II Physical properties Curing Curing tempora- Add- Crease recovery Tearing strength time ture on, Washangle (deg) (gms.) (min) (deg. 0.) percent wear rating W. F. W. and W. F. W.anrl

EXAMPLE 5 Table III Physical properties Add- Tearing strength pH 33%% Crease recovery soln. Washangle (deg.)

'(Ztl rating on, percent W. and W. W. and F. F.

human- As can be seen from Table III, an acceptable finish may be obtained when the pH of the finishing solution is high as 6.

EXAMPLE 6 A sample of 80 x 80 cotton print cloth was treated with a 7% solution of alloxan-2CH O, and 1.5% MgCl as catalyst, as described in Example 1. This fabric, a sample finished with 7 /2% dimethylol ethyleneurea, catalyzed by 0.5% Zn(NO -6H O, and an untreated washed control were given 5 AATCC 14-53 washes and 10 home launderings with hypochlorite bleach. The effect of these washes on the physical properties of the finish are listed in Tables IV and V. (The original properties of the fabrics listed in Table V are the same as those included in Table IV.)

Table V After 10 home launderings with 0.02% available chlorine Finishing agent used Tearing Brk. str. ret.

Crease rec. strength after AATCO angle (deg) (gms) 69-1952 scorch W. and F. W. and F. test, percent orig.

Untreated fabric 172 1, 233 102. 7 DMA 250 453 100. 1 7%% DMEU 288 101.0

Tables IV and V show that the aIIQXan-ZCH O finish is durable through both the home launderings and the more vigorous AATCC 14-53 washes. The

allcxan 2CH O finish is far superior in resistance to damage by retained chlorine after 5 AATCC 145 3 washes than is the DMEU finish. After home launderings the alloXan-2CH O finish is equal to the DMEU finish in resistance to damage by retained chlorine.

EXAMPLE 7 The alloxan-2CH O in 33 /s% solution, prepared as described in Example 1 has a shelf life of more than one month. Fabric treated with a 7% solution of the stored finishing agent had a crease recovery angle of 133 (Warp). Fabric treated with a 7% solution, prepared from a 33 /3% solution allowed to stand overnight before padding had a crease recovery angle of 139 (Warp).

1 claim:

A process for finishing textiles comprising Wetting hydrophilic fibrous cellulosic textile to about by weight wet pick-up with an aqueous solution containing from 1 to 20% by weight of: the essentially monomeric reaction product of 1 mole of the ureide of oxalic acid with about from 1-4 moles of formaldehyde and from 0.5 to 3.0% by Weight of an acidic polymerization catalyst and heating the wetted textile at a temperature of from to C. for a period of from 0.5 to 5 minutes, the longer time intervals being employed with the lower temperatures.

References Cited in the file of this patent UNITED STATES PATENTS 2,662,080 Smith Dec. 8, 1953 2,766,283 Darden Oct. 9, 1956 2,904,387 Holbrook et al. Sept. 15, 1959 2,904,388 Holbrook et al. Sept. 15, 1959 2,959,589 Ramsden Nov. 8, 1960 OTHER REFERENCES Frick et al.: Department of Agriculture, printed from Amer.'Dyestufi Reporter, vol. 48, No. 13, pp. 23-25, June 29, 1959.

Reid et al.: Department of Agriculture, printed from Textile Research Journal, vol. 28, No. 3, pp. 24225 1, March 1958. 

